Study Rationale:PD01A is an alpha-synuclein-targeting vaccine. Accumulation and/or aggregation of alpha-synuclein is central to the pathogenesis of Parkinson’s disease, and its reduction is expected to positively modify the course of the disease. PD01A has been tested in a first-in-humans Phase IA study. Results obtained demonstrated multiple (n=4) subcutaneous vaccinations with two different doses of PD01A (15 and 75 µg) to be safe and well tolerated. Evaluation of patients’ blood demonstrated the induction of the intended alpha-synuclein-reactive antibodies.

Hypothesis:Our hypothesis is that it is possible to boost the antibody response generated by the initial monthly PD01A administrations.

Study Design:Patients who have already received four immunizations with PD01A within the prior study will be offered a fifth immunization. To this end, they will be randomized, depending on their initial dose, to receive the low (15 µg) or the high (75 µg) dose of PD01A. Before applying the boost, baseline evaluations for various parameters (e.g., immune response, motor- and non-motor scales) will be conducted. After the boost, patients will be followed for six months and regularly assessed for adverse events, for immune response and for clinical activity of the boost injection of PD01A.

Impact on Diagnosis/Treatment of Parkinson’s Disease:A vaccine that would be capable of slowing or halting the process underlying Parkinson’s disease would fundamentally impact the way we treat the disease. It would represent the first causal treatment.

Next Steps for Development:This project is the next step towards Phase II testing of PD01A. Defining the conditions for keeping antibodies elevated over time is an essential next step for the clinical development of PD01A.

Trial phase: IB

FINAL OUTCOME

AFFITOPE® PD01A was safe and well tolerated, achieving the primary goal of this study. There was less worsening of the disease in the vaccine-treated group compared to the control group. Both the investigator and the participants knew who received the vaccine; therefore, it is not known whether the outcome of the study can be attributed solely to the vaccine treatment. The length of the study (more than two years for those participating in the AFF008 study and the AFF008A boost study) suggests that the stabilization of symptoms are meaningful. A good immune response to the vaccine was seen in the primary study AFF008, and again in this study AFF008A after the boost immunization.

The company presented this data in September 2016 at the World Parkinson Congress. Read more: https://www.michaeljfox.org/foundation/news-detail.php?vaccine-for-parkinson-reports-positive-results-from-boost-study